Julie Schenecker Case: Making Sense of Unthinkable Violence

It's normal for parents to feel angry at their children now and then, and experts say those emotions rarely reach a level or a frequency that leads to violence.

But the case of Julie Schenecker, the Tampa, Fla., woman accused of fatally shooting her teenage son and daughter, reportedly because she was tired of them being "mouthy," put the spotlight on the dire results of losing emotional control.

She's not the only parent who made the news recently after allegedly killing a child out of anger.

Stacey Pagli, a mother from Westchester County, N.Y., pleaded guilty to manslaughter this week for strangling her 18-year-old daughter at Manhattanville College in New York after Pagli said her daughter "pushed my last button" and was always disrespectful.

While they have not evaluated Schenecker or Pagli and only can speculate about their motives, psychologists said it could have been a combination of factors, including mental illness, extreme stress and feeling rejected by their children, that led to these mothers' actions.

"While there are common patterns among parents who kill their children, there do seem to be some parents who just 'snap,' like the buildup of stress becomes too much and they can no longer cope," said Kaslow.

Several parents told ABC News while they've never felt the urge to kill their children, they have had trouble coping with anger.

One mother, who didn't want to be identified, knew she needed counseling after she realized arguments with her teenage daughter became too frequent and too loud. She said she they both needed a "sane voice."

Her daughter was dating a boy who had been in trouble with the law, which caused a lot of concern -- and anger.

"I was totally taken aback by the way I frequently got absolutely white hot with rage," she said. "My younger daughter used to dread the ride to school because it would inevitably degenerate into a shrieking match."

Frequent Arguments May Signal a Need to Get Help

"If a parent and adolescent are having angry arguments more than two times a week, if they are unable to resolve these conflicts, if the arguments escalate out of control or if they ever spiral into physical aggression, the family should seek counseling," said Laurence Steinberg, author of "You and Your Adolescent: The Essential Guide for Ages 10 to 25."

Relationships with adolescents can be especially challenging, and experts say abuse of adolescents isn't uncommon.

"Across age groups, adolescents between the ages of 12 and 15 are among the most frequent victims of parental violence -- there are more than 25,000 reported cases of this each year," said Steinberg, who is also a professor of psychology at Temple University in Philadelphia.

But young children also can be the target of parental rage.

Another mother, who also wanted to remain anonymous, said her six-year-old daughter has sensory processing disorder, which causes the brain to perceive sensory information differently. The disorder can cause people to have difficulty dealing with everyday activities.

Because of her disorder, her mother said, her child is easily frustrated and "on edge."

"I have suffered my fair share of rage at her and have sought counseling both for her and myself," the woman said. "There are times I lose my temper with my child and just feel like I cannot stand another minute of my life as her mom."

Experts said such situations can remind parents to be aware of negative emotions like anger toward their children and pay attention to possible warning signs that their feelings are irrational.

"When parents feel consumed by their anger and cannot think about or feel any positive emotions toward their children, this is very concerning," said Nadine Kaslow, professor of psychology at Emory University in Atlanta. "If parents start to have fantasies of their children being dead or actually of killing them, not only do they need to step back but they need to get help."

There also are signs that it's time for a parent to step back and take a few deep breaths or count to 10.

Those signs may include, "when they feel that they are on the verge of saying or doing something they may regret [or] when they seem to be on the verge of forgetting that they are parents and not siblings to their children," said Dr. Harold Bursztajn, associate clinical professor of psychiatry at Harvard Medical School.

While she never wanted to kill her son, another woman told ABC News she had trouble bonding with him and often raised her voice and argued with him.

Her son, now 6, recently was diagnosed with attention deficit disorder.

His mother said he was sometimes a difficult child. She adopted him when he was an infant shortly after her biological infant son died.

"It was a combination of grief and a lack of bonding, and I got angry at him a lot," she said. "He would do things that little boys do, like leave the toilet seat up or leave dirty clothes on the floor. I would lose patience and argue with him. There were a lot of raised voices and I had a short fuse."

Warning Signs Never Should Be Ignored

Kaslow said there are other warning signs parents never should ignore, including neglect or abuse of their own children, thoughts about killing their children, saying they wish their children were dead and actual attempts to kill their children.

The mothers who spoke to ABC News want to encourage other parents to address their anger and get help, if needed. One of them, while she did get counseling and is able to cope with her young daughter's troublesome behavior caused by sensory processing disorder, still is struggling.

"I often feel like a horrible failure as a mom," she said, "because I can't seem to love my daughter like other people love their children."